Method op and apparatus for controlling vibratory systems



Nov. 19, 1929.

METHOD OF AND APPARATUS FOR CONTROLLING VIBRATORY SYSTEMS J. W. LEGG Filed Sept. 25, 1927 4 Sheets-Sheet 1 INVENTOR Jase 0b 14/. Legg Nov. 19, 1929. .1. w. LEGG 1,736,500

METHOD OF AND APPARATUS FOR CONTROLLING VIBRATORY SYSTEMS Filed Sept. 23, 1927 4 Sheets-Sheet 2 INVENTOR Joseph 14/ Leyy AITTORNEY J. W. LEGG Nov. 19, 1929.

METHOD OF AND APPARATUS FOR CONTROLLING VIBRATORY SYSTEMS Filed Sept. 23, 1927 4 Sheets-Sheet 3 r 1 I 1 I J. W. LEGG Nov. 19; 1929.

METHOD OF AND APPARATUS FOR CONTROLLING VIBRATORY SYSTEMS 4 Sheets-Sheet 4 INVENTOR Joseph W Legg ATTORNEY Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE JOSEPH W. LEGG, 0F WILKINSBURG, PENNGYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION 01 PENNSYLVANIA METHOD OF AND APPARATUS FOR CONTROLLING VIBRATORY SYSTEMS Application filed September 28, 1927. Serial No. 221,599.

My invention relates to a method and apparatus for actuating or controllin a moving system, as the vibratory or eflecting system of a galvanometer.

In accordance with my-invention, a vibratory or deflecting system, as aforesaid, is actuated by a plurality of groups of forces applied to difierent regions thereof.

Further in accordance with my invention, the vibratory system of a galvanometer is actuated or deflected by a plurality of groups of coacting magnetic fields, each of the latter depending in magnitude upon a changing or varying quantity, as the instantaneous magnitudes of the voltage or current of a olyphase electrical circuit, and more particu arly of a three-phase circuit.

Further in accordance with my invention, the vibratory or deflecting system of a galvanometer comprises a plurality of electrical circuits arranged for coaction with a plurality of magnetic circuits.

More particularly in accordance with my invention, the aforesaid vibratory or defleeting system comprises a plurality of (elec trical conductors bridged, intermediate their ends, by a short-circuiting member thereby forming a plurality of electrical circuits.

My invention resides in the method, system and'mechanism of the character hereinafter described and claimed.

The feature of positioning a currentcarrying galvanometerdeflecting element within a magnetic field and varying the magnitude of the current and the intensity of the magnetic field simultaneously is described and claimed in my copending application Serial No. 182,653, filed April 11, 1927.

For an understanding of my method and for an illustration of some of the forms my system or mechanism may take, reference is to be had to the accompanying drawing,

in which Figure 1 is a diagrammatic view of an oscillograpli system constructed in accordance with my invention;

Fig. 2 is a diagrammatic view illustrating a circuit arrangement for connecting a galvanometer deflecting system to, an external circuit;

Fig. 3 is an enlarged front elevational view of a part of the structure shown in Fig 2;

Fig. 4 is a side elevational view of the structure shown in Fig. 3;

Fig. 5 is a vertical sectional view of galvanometer mechanism constructed in accordance with my invention;

Fig. 6 is a transverse, horizontal sectional view taken substantially on the line VIVI of. Fig. 5, and looking in the direction of the arrows;

Fig. 7 is a transverse, vertical sectional view taken substantially on the line VIIVII of Fig. 5, and looking in the direction of the arrows;

F' 8 is a fragmentary transverse, horizont afi sectional view taken on the line VIII-VIII of Fig. 5, and looking in the direction of the arrows;

Fig. 9 is a plan view of the mechanism shown in Fig. 5;

Fig. 10 is a front elevational view of the mechanism shown in Fig. 5.

Referring to Fig. 1, there is'diagrammatically illustrated galvanometer mechanism'G comprising structures or stacks 1, 1a of members or sheets, each formed or magnetizable material, incapable, to any substantialextent, of becoming permanently magnetized. The structures 1, 1a each comprise spaced pole pieces forming a flux gap 2 through which extends a pair of parallel conductors 3, 3 suitably mounted for oscillatory movement and having mid-way of their ends, a mirror 4 cemented, or otherwise suitably secured thereto. As illustrated in Figs. 3 and 4, the aforesaid conductors 3, 3 substantially midway of their ends and to the rear of the mirror 4 have a conductive member 5, soldered or otherwise suitably secured thereto. The member 5 short-circuits the conductors 3, 3 and thereby forms two electrical circuits which, however, are entirely integral in a mechanical sense.

A beam of light emanating from any suitable source, such as the incandescent filament 6 of an electric lamp passes to the mirror 4 by which it is reflected through a condensing lens 8 and engages, substantially as a point of light, viewing or recording structure of any suitable character. As herein illusmechanismgitwill be understood that the source of light 6, galvanometer mechanism G, the lens and the light-sensitive surface 9 should be enclosed in a suitable light-proof housing. Galvanometer mechanism of the character herein described is designed particularly for use with a polyphase electrical circuit, .and

more particularly a three-phase circuit, herein diagrammatically illustrated as comprising the line conductors L1, L2, and L3. The conductor L1 coacts with and serves as the primary winding, for a current transformer 13, the secondary winding of which is connected by'conductors 14 and 15 to the terminalsof a coil or winding 16 coacting with or wound upon the magnetizable structure 1a. The line conductor L3 coacts with, and serves as the primary winding, for another current transformer 17, the secondary winding of which is connected by conductors 18. and 19 to the terminals of a coil or winding 20 coacting with or Wound upon the magnetizable structure 1.

Secured, respectively, to the line conductors L1, L2 and L3 are the conductors'21, 22 and 23. Conductors 21 and 23 are connected, respectively, to terminals of the primary windings of voltage transformers 24 and 25, said primary windings being connected together by a conductor 26 to which the aforesaid conductor 22 is connected. The secondary winding of transformer 24 is connected by conductors 27 and 28 to one group of terminals of the conductors 3, 3, respectively, which form, as stated above, the deflecting system of the galvanometer mechanism. Similarly, the secondary winding of transformer 25 is connected by conductors 29 and 30 to the other group of terminals of the conductors 3, 3, re-

.spectively. Preferably, an adjustable resistthe structures 1 and 1a and the strength of each field is proportional, respectively, to the currents in the line conductors L1 and L3. The upper group of conductors 3, 3 as viewed in Fig. 1, are energized by a' currentpropor and L2. Similarly, the lower group of conductors 3, 3, as viewed in Fig. 1, are energized by a current proportional to the voltage across the conductors L2 and L3. Accordingly, for each circuit of the deflecting system, current passes along one of the conductors of each group in one direction, thence through the conductive member 5 and then along the other conductor of each group in reverse direction, thereby setting up magnetic fields angularly related to the magnetic fields existing in the gaps between the pole pieces of the groups of magnetizable members 1, 1a. As a result, deflecting or vibratory movement is imparted to the conductors 3, 3 and tothe theretosecured mirror 4.

In accordance with the teaching of Blondels theorem, the power of a polyphase electrical system may be measured by utilizing one less moving system than there are line conductors in the polyphase system. In an electrical sense, there are provided, as illustrated in Fig. 1, two moving systems, and it follows, therefore, that due to the mechanical unity of said electrical systems that they assume a position dependent upon the instantaneous sum of the power traversing the circuitcomprising the conductors L1, L2 and L3. Accordingly, from the mirror 4 there is reflected a beam of light which moves axially of the drum 10 in proportion to the magnitude of the'average power, as aforesaid.

Referring to Figs. 5-10, there is illustrated one form of galvanometer' mechanism which I have devised for performing the function heretofore explained. As shown, a casing or "tional to the voltage across the conductors L1 container 32 of suitable non-magnetic matcrial has a magnetic member 33 soldered, or otherwise suitably secured thereto. Q Suitably fastened to the member 33, as by screws 34, is a magnetic plate or disc 35 perforated to permit the passage therethrough of various members, as hereinafter more fully described.

Referring to Figs. 5 and 7, the casing 32 adjacent its bottom and each sidewall contains a pair of spaced wedge-shaped members 36 and 36a which support a stack or group of substantially U-shape members 37 corresponding with the group of members 1a Fig. 1, and, therefore, formed of magnetizable sheets substantially incapable of becoming permanently magnetized. Overlying the stack of members 37 is a spaced pair of wedge-shapedmembers 38 and 38a on which is disposed one or more U-shaped members or plates 39 formed of magnetizable material and serving as a magnetic shield, as hereinafter more fully described. Disposed above the members 39 is still another pair of spaced wedge-shaped members 40, 40a supporting a stack of U-shaped members 41 forming a structure which is substantially or entirely a duplicate of the structure 37 and corresponding with the group of magnetizable members 1, Fig. 1. Dis )osed on the last named stack bf magnetizable members 41 is still another pair of spaced wedge-shaped members 42, 42a.

Coacting magnetically with the magnetizable structures 37 and 41 are the respective coils or windings 43 and 44, preferably wound around the rear legs of saidstructures 37 and 41 and corresponding enerally with the respective windings 16 a 20, Fig. 1. Disposed bet ween adjacent surfaces of the wlndings 43 and 44 and the respective magnetlc structures 37 and 41 upon whichthey are wound are members or sheets 45 formed of suitable insulating material, Figs. 5 and .6.

It will be observed that the apexes of neighboring pairs of the aforesai wedges are oppositely disposed whereby the magnetizable structures 37 and 41 converge in a direction extending toward the front or left hand sideof casing 32, Fig. 5. Accordingly; in the region of casing 32 last mentioned, the magnetizable "structures are closely adjacent each other, while in the rear of said casing there is ample room for the coils 43 and 44 on either side of the magnetic shields 39, which serve to prevent or impede passage of flux between the respective magnetic structures.

vAll of the hereinbefore described Wedgeshaped members are formed of suitable insulating material, such as a phenol condensa- 'tion product, preferably of the type known to. the trade as micarta.

As illustrated in Fig. 7, the wedge-shaped members 36, 38, 40 and 42 are disposed directly above each other in the order named and closely adjacent one side wall of the easing 32. imi arly, the wedge-shapedmembers 36a, 38a, 40a and 42a are dlsposed in overlying relation and adjacent the other side wall of casing 32. The various wedge-shaped members, groups of magnetiz'able members, magnetic shields and windings for the magnetizable members at the rear of-casing 32, are held in assembled relation by belts or other fastening members 46 and 46a. Adjacent the front wall of casing 32, the various wedge-shaped members, magnetizable members, etc. are maintained in assembled 'relation by bolts 47 and 47a. The bolts '46, 47, and 46a, 47a have their upper ends threaded, respectively, 'into the wedge-shaped members 42 and 4211-, while their lower ends are held in engagement with the lowermost wedgeshaped members 36 and 36a by nuts 48. As shown in Fig. 7, it will be observed that the bolts 46 and 461 extend through the various wedge-shaped members exteriorly of the magnetizable structures 37 and 41 thereby preventing the formation of eddy currents,

while the bolts 47, 47a: extend through the magnetizable structures as well as through the wedge-shaped members.

he aforesaid structure, when thus held 5 in assembled relation, by bolts 46, 46a, 47 and 47a, is suitably secured b screws 49, Fig. 7

The terminals of winding 43 are connected by conductors 51 to binding posts orterminals 52. Similarly, the terminals of winding 44 are connected by conductors 53 to bindin posts or terminals 54. It will be observe that the sets of terminals 52 and 54 are carried b the plate and that the conductors 51 and 53 in order to engage therewith, extend through said plate 50 and the plate 35. Each of the aforesald sets of terminals 52 and 54 comprises a bushing of suitable insulating material threaded into an opening in plate 50, the conductive members of said terminals being secured, respectively, to the insulating bushings.

Referring to Fig. 5, a pin or member 55 is shown as threaded into the plate 50. J ournalled upon the member 55 is a disk or member 56 having a stem 57 projecting downwardly within the casing 32. The stem 57 forms the direct support for the deflect-ing or vibratory system which, in the example illusstrated, comprises the pair of conductors 3, 3 formed of suitable material having great tensile strength and low electrical resistance, as a silver alloy in filamentary form, said conductors 3, 3 passing through the flux gaps formed by the pole pieces of the magnetizable structures 37 and 41. It shall be understood that the conductors 3, 3, midway of their ends, have soldered or otherwise suitably secured thereto the metallic conductive member 5, preferably of silver alloy which falls within the space bounded by the upper and lower surfaces of the respective stacks of magnetizable members 37 and 41. It shall also be understood that the member 5 is disposed rearside slots extending vertically along the front faces of supports 60, 60.

As illustrated in Fig. 5, the upper end of one of the conductors 3 is soldered, or otherwise suitably secured, to a conductive plug or post 62 projecting from and grounded on the stem 57. The upper end of the other conductor 3 is similarly secured to a conductive member 63 passing through a perforation in stem 57, but insulated therefrom by a member 64.

As illustrated, the upper ends of conductors 3, 3 are connected in an external circuit b bindin posts or terminals'65 and 66 hot carrie by the disc 56, the former being conductively related thereto. However, terminal '66 is insulated from the disc 56 by a bushing through which extends a conductive member connected to the aforesaid conductive member 63. As illustrated more particularly in Figs. -2 and 8, the lower end of eachconductor 3, 3 is soldered, or otherwise suitably secured, respectively, to screws or lugs 67 carried, respectively, by conductive plates or levers 68, 68 disposed within the slotted end of stem 57 and each insulated therefrom b a 'plate or member 69 of micarta, or the li e. Passing through the lower portion of stem 57 is a pin or shaft 70 upon which the aforesaid plates 68, 68 are journalled. The shaft 70 passes through a sleeve or thimble 71, of suitable insulating material, as ivor with which the plates 68, 68 engage and y which they are insulated from each other. Ordinarily, it is desirable that an insulating plate 72 be .disposed on the thimble 71, by which chance contact of the screws 67, 67 or plates 68, 68-is prevented.

Referring to Fig. 5, a flexible loop-shaped member or thread 73 of suitable insulating material is hooked in a slot in one plate 68, passed through a pulley 74: and then hooked mto a slot in the other plate 68. One end of a helical spring 75 is connected to pulley 7a .whilethe other end thereof'is secured to a screw 76 assing freely through a lug 77 extending rom the stem 57. A nut 78 coacts with the screw 76 and the lug 77 whereby the tension upon the helical spring 75 may beva- ,ried at Will to thereby control the tension of conductors 3, 3. Due to the construction described, each conductor 3, 3 has substantially the same tension since the'pulley 7 4 slips with respect to the loop-shaped member 73.

Secured, respectively, to the levers or plates 68, 68 are the ends of conductors 80, 80 which pass along the stem 57 and are connected to binding posts or terminals 81, 81 carried 4 by and insulated from the plate 56. By the arrangement last described, the lower ends of the conductors 3, 3 may be placed in the external circuit. 7

Disposed on the member 55 and engaging theupper surface of disk 56 is a spring washer 82, Fig.5, with which the integral head 83 of member engages. Head 83, when properly adjusted, compresses washer 82, thereby 'applying pressure to disk 56 to hold it in intimate engagement with plate 50.

Rotation may be imparted to disk 56 and the thereby-carried deflecting system in any suitable manner. As illustrated, disk 56 has secured through a rack or gear segment 84, Figs. 5 and 9, meshing with a pinion 85 hav- 55 ing an actuating knob 86. Formed integrally with pinion 85 is a stem 87 rotatabl mounted in a member '88 suitably dispose in fluidtight relation with respect to the plate 50. Upon actuation of pinion 85, disk 56 andthe deflectin system associated therewith may be rotate in either direction, thereby ad'ustin the mirror 59 about a vertical axis to bring the reflected beam of light into a desired position in a horizontal plane.

After disengagement of pinion 85 from rack 84 and removal of the member 55, the disk 56 may be moved backwardly and then upwardly, Fig. 5, to withdraw stem 57 and the therewith-associated mechanism from the container 32. Before initial operation of the mechanism and while the aforesaid parts are thus removed, a suitable medium, as a high grade paraffin mineral oil, for example, that known in the trade as Nujol should be poured thereinto, a medium of this character, serves as a damping agent for the deflecting system and substantially eliminating the natural period thereof.

Opposite the mirror 4, the front wall of container 32 is provided with an opening covered by a condensing lens 89 suitablyheld in liquid-tight relation with respect to the Outer surface of said front wall.

For thus holding lens 89 in position, there may be utilized a plate 90 riveted, or otherwise suitably secured, to the lower portion of the front wall of container 32. Disposed above the plate 90 is a member or plate 91, which should be black and a poor light reflector, preferably, a phenol condensation product and having an opening registering with the aforesaid opening in the front wall of casing 32. As shown, the inner surface of plate 91, adjacent said opening, engages the outer peripheral surface of lens 89. Member 92, at its upper edge, is disposed between the front wall of container 32 and a plurality of abutments 92,

vspaced from each other and from said front wall. The lower edge of plate 91 is disposed between the lower front wall of casing 40 and a clamp 93, suitably secured, as by one or-more screws 94, tothe adjacent plate 90.

The above-described galvanometer mechanism may be disposed within or on a supporting structure of any suitable character, and when thus supported, there may be utilized studs 95, Fig. 7, on which the casing 32 rotates or oscillates about a horizontal axis.

I claim as my invention:

1. The combination with a deflecting system comprising conductors forming a plurality of electrical circuits, and a light-refleeting mirror carried by said conductors, of

a plurality of magnetic systems individually coacting with said electrical circuits.

2. The combination with a deflecting system comprising conductors forming a plurality of electrical circuits, and a light-reflecting mirror carried by said conductors, of a plurality of magnetic systems individually coactin with said electrical circuits, and means or shielding said magnetic systems from each other.

3. A deflecting system for a galvanometer comprising parallel conductors forming a plurality of electrical circuits, and a lightported at each end, means for connecting each end to a source of current, and an electrically conducting strip connecting said wires at a point intermediate their ends.

7 In a deflecting system, two wires supported at each end, means for connecting each end to a source of current, an electrically conducting strip connecting said wires at a point intermediate their ends and a mirror mounted on said wires.

8. In an electrical system, a plurality of magnetic cores, each core having an air gap,

said air gaps being placed adjacent to and in line with each other, a winding on each of said cores, each of said windings being connected to the source of a quantity to be measured, and a vibratory system placed within said air gaps.

9. In electrical apparatus, a plurality of magnetic cores, each core having an air gap, said air gaps being placed adjacent to and in line with each other, a vibratory system placed within said air gaps under tenson, said system having one electrical circuit for each air gap.

10. In electrical apparatus, a plurality of magnetic cores, each core having an air gap, saidair glaps being 1placed adjacent to and in line wit each 0t er, a vibratory system placed within said air gaps under tension said system comprising two parallel wires under tension, said wires being electrically connected at a point intermediate their ends.

11. In electrical apparatus, a plurality of magnetic cores, each core having an air gap, said air gaps being placed adjacent to and in line with each other, a vibratory system placed within said air gaps under tension, said system comprising two parallel wires means to electrically connect said wires at a point intermediate their ends, and means to place said wires under like tension.

12. In electrical apparatus, a plurality of magnetic cores, each core having an air gap, said air gaps being placed adjacent to and in line with each other, a vibratory system placed within said air gaps under tension,

said system comprising two parallel wires,

means to electrically connect said wires at a "point intermediate their ends, and means to place said wires under like tension, said 7 last named means comprising two levers mounted so as to be rotatable about a common axis, a flexible member connecting two adjacent ends of said levers, and a spring connected to said flexible member by means which permits said spring to slide along said flexible member.

In testimony whereof, I have hereunto su scribed my name this 8th day of September,

JOSEPH W. LEGG. 

